Oxygen permeable contact lenses in the prior art are essentially made from siloxane monomer and methyl methacrylate. These lenses are permeable to oxygen; hense, allowing oxygen from the air to pass through the lenses and reach the cornea and allows such lenses to be worn for longer periods of time as compared to non-oxygen permeable contact lenses such as PMMA which were previously available.
Such contact lenses were disclosed in the prior art by Norman G. Gaylord, U.S. Pat. Nos. 3,808,178 and 4,120,570. Later on, Ellis disclosed in his patents, U.S. Pat. Nos. 4,152,508 and 4,330,383, the partial replacement of the MMA monomer with dimethyl itaconate. The Novicky patents, U.S. Pat. Nos. 4,216,303, 4,242,483 and 4,248,989, disclosed contact lenses comprised of high molecular weight polysiloxanylalkyl esters of acrylic and methacrylic acids. Chang, U.S. Pat. No. 4,182,822, disclosed contact lenses comprised of a copolymer from polysiloxanylalkyl ester of acrylic and methacrylic acid essentially the same as disclosed in the Gaylord patents, supra., that were copolymerized with N-vinyl pyrrolidinone or N,N-dimethyl methacrylamide.
Ichinoche, et al., Canadian Pat. No. 1,184,341, teaches the use of organosiloxanyl ester monomer of acrylic and methacrylic acid copolymerized with fluorocarbon ester monomers of acrylic and methacrylic acids and copolymerized to produce oxygen permeable contact lenses. LeBoeuf, U.S. Pat. No. 4,246,389, discloses acrylic siloxane based polymers which also contain HEMA and/or polyvinyl pyrrolidinone which are suitable for use in forming water-containing oxygen permeable contact lenses.
The use of sulfones in the manufacture of plastics and plastic membrane filters to separate oxygen from other gases is known in the prior art. The use of unsaturated alkyl sulfones for the manufacturing of highly oxygen permeable contact lenses is not disclosed and, insofar as is known to the inventor, the use of ethylenically unsaturated alkyl sulfones for the manufacturing of rigid and semi-rigid contact lenses has not been reported.